S-91500A364 5/16"-18 x 2 1/2" ASME B18.6.3 Stainless Steel Phillips Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 316 stainless steel construction, ideal for harsh chemical and marine environments
• Exceptional mechanical strength with 70,000 psi tensile strength and Rockwell B80 hardness for reliable load-bearing performance
• Precise thread engagement with Class 2A UNC coarse threads ensuring secure fastening and vibration resistance
• Enhanced surface protection through passivated finish that increases longevity and prevents galling
• Optimized flush installation with standard 82° countersink angle and flat head design for smooth surface finishing
• Efficient drive compatibility with Phillips No. 4 drive enabling quick installation with common tools
• Full-threaded design providing maximum grip length and uniform stress distribution along the entire fastener

Professional Applications & Engineering Value

This 316 stainless steel flat head screw delivers critical performance advantages in demanding industrial settings where corrosion resistance and structural integrity are paramount. The combination of UNC coarse threading and Class 2A thread fit ensures rapid installation and reliable clamping force in materials prone to vibration loosening. The passivated finish significantly enhances the natural corrosion resistance of 316 stainless steel, making these Phillips drive screws ideal for chemical processing equipment, marine hardware, and food processing machinery where exposure to aggressive environments would compromise ordinary fasteners. The fully threaded design maximizes engagement in both thick and thin materials, while the standardized flat head profile provides seamless flush mounting in countersunk applications.

Specification Summary & Compliance

This fastener maintains precise Class 2A thread fit tolerances with UNC coarse thread spacing (5/16"-18) and complies with ASME B18.6.3 manufacturing specifications. The product meets RoHS 3 (2015/863/EU) compliance for hazardous substance restrictions and REACH (EC 1907/2006) standards for chemical safety. Manufacturing adheres to dimensional requirements including 82° countersink angle, 0.597" head diameter, and 2 1/2" length with full threading.